Methods of manufacture of top port multi-part surface mount MEMS microphones

ABSTRACT

Methods for manufacturing multiple top port, surface mount microphones, each containing a micro-electro-mechanical system (MEMS) microphone die, are disclosed. Each surface mount microphone features a substrate with metal pads for surface mounting the package to a device&#39;s printed circuit board and for making electrical connections between the microphone package and the device&#39;s circuit board. The surface mount microphones are manufactured from panels of substrates, sidewall spacers, and lids. Each MEMS microphone die is lid-mounted and acoustically coupled to the acoustic port disposed in the lid. The panels are joined together, and each individual substrate, sidewall spacer, and lid cooperate to form an acoustic chamber for its respective MEMS microphone die. The joined panels are then singulated to form individual MEMS microphones.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/841,796 (now U.S. Pat. No. 8,633,064), filed Mar. 15, 2013, which isa continuation of U.S. patent application Ser. No. 13/732,232 (now U.S.Pat. No. 8,624,387), filed Dec. 31, 2012, which is a continuation ofU.S. patent application Ser. No. 13/286,558 (now U.S. Pat. No.8,358,004), filed Nov. 1, 2011, which is a continuation of U.S. patentapplication Ser. No. 13/111,537 (now U.S. Pat. No. 8,121,331), filed May19, 2011, which is a continuation of U.S. patent application Ser. No.11/741,881 (now U.S. Pat. No. 8,018,049), filed Apr. 30, 2007, which isa divisional of U.S. patent application Ser. No. 10/921,747 (now U.S.Pat. No. 7,434,305), filed Aug. 19, 2004, which is acontinuation-in-part of U.S. patent application Ser. No. 09/886,854 (nowU.S. Pat. No. 7,166,910), filed Jun. 21, 2001, which claims the benefitof U.S. Provisional Patent Application No. 60/253,543, filed Nov. 28,2000. U.S. patent application Ser. No. 13/668,035, filed Nov. 2, 2012,U.S. patent application Ser. No. 13/668,103, filed Nov. 2, 2012, U.S.patent application Ser. No. 13/732,120, filed Dec. 31, 2012, U.S. patentapplication Ser. No. 13/732,179, filed Dec. 31, 2012, U.S. patentapplication Ser. No. 13/732,205, filed Dec. 31, 2012, and U.S. patentapplication Ser. No. 13/732,232, filed Dec. 31, 2012, are alsocontinuations of U.S. patent application Ser. No. 13/286,558 (now U.S.Pat. No. 8,358,004). These applications are hereby incorporated byreference herein in their entireties for all purposes.

TECHNICAL FIELD

This patent relates generally to a housing for a transducer. Moreparticularly, this patent relates to a silicon condenser microphoneincluding a housing for shielding a transducer.

BACKGROUND OF THE INVENTION

There have been a number of disclosures related to building microphoneelements on the surface of a silicon die. Certain of these disclosureshave come in connection with the hearing aid field for the purpose ofreducing the size of the hearing aid unit. While these disclosures havereduced the size of the hearing aid, they have not disclosed how toprotect the transducer from outside interferences. For instance,transducers of this type are fragile and susceptible to physical damage.Furthermore, they must be protected from light and electromagneticinterferences. Moreover, they require an acoustic pressure reference tofunction properly. For these reasons, the silicon die must be shielded.

Some shielding practices have been used to house these devices. Forinstance, insulated metal cans or discs have been provided.Additionally, DIPs and small outline integrated circuit (SOIC) packageshave been utilized. However, the drawbacks associated with manufacturingthese housings, such as lead time, cost, and tooling, make these optionsundesirable.

SUMMARY OF THE INVENTION

The present invention is directed to a silicon condenser microphonepackage that allows acoustic energy to contact a transducer disposedwithin a housing. The housing provides the necessary pressure referencewhile at the same time protects the transducer from light,electromagnetic interference, and physical damage. In accordance with anembodiment of the invention a silicon condenser microphone includes atransducer and a substrate and a cover forming the housing. Thesubstrate may have an upper surface with a recess formed thereinallowing the transducer to be attached to the upper surface and tooverlap at least a portion of the recess thus forming a back volume. Thecover is placed over the transducer and includes an aperture adapted forallowing sound waves to reach the transducer.

Other features and advantages of the invention will be apparent from thefollowing specification taken in conjunction with the followingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a first embodiment of a siliconcondenser microphone of the present invention;

FIG. 2 is a cross-sectional view of a second embodiment of a siliconcondenser microphone of the present invention;

FIG. 3 is a cross-sectional view of a third embodiment of a siliconcondenser microphone of the present invention;

FIG. 4 is a cross-sectional view of the third embodiment of the presentinvention affixed to an end user circuit board;

FIG. 5 is a cross-sectional view of the third embodiment of the presentinvention affixed to an end user circuit board in an alternate fashion;

FIG. 6 is a plan view of a substrate to which a silicon condensermicrophone is fixed;

FIG. 7 is a longitudinal cross-sectional view of a microphone package ofthe present invention;

FIG. 8 is a lateral cross-sectional view of a microphone package of thepresent invention;

FIG. 9 is a longitudinal cross-sectional view of a microphone package ofthe present invention;

FIG. 10 is a lateral cross-sectional view of a microphone package of thepresent invention;

FIG. 11 is a cross-sectional view of a top portion for a microphonepackage of the present invention;

FIG. 12 is a cross-sectional view of a top portion for a microphonepackage of the present invention;

FIG. 13 is a cross-sectional view of a top portion for a microphonepackage of the present invention;

FIG. 14 a is a cross-sectional view of a laminated bottom portion of ahousing for a microphone package of the present invention;

FIG. 14 b is a plan view of a layer of the laminated bottom portion ofFIG. 14 a;

FIG. 14 c is a plan view of a layer of the laminated bottom portion ofFIG. 14 a;

FIG. 14 d is a plan view of a layer of the laminated bottom portion ofFIG. 14 a;

FIG. 15 is a cross-sectional view of a bottom portion for a microphonepackage of the present invention;

FIG. 16 is a cross-sectional view of a bottom portion for a microphonepackage of the present invention;

FIG. 17 is a cross-sectional view of a bottom portion for a microphonepackage of the present invention;

FIG. 18 is a cross-sectional view of a bottom portion for a microphonepackage of the present invention;

FIG. 19 is a plan view of a side portion for a microphone package of thepresent invention;

FIG. 20 is a cross-sectional view of a side portion for a microphonepackage of the present invention;

FIG. 21 is a cross-sectional view of a side portion for a microphonepackage of the present invention;

FIG. 22 is a cross-sectional view of a side portion for a microphonepackage of the present invention;

FIG. 23 is a cross-sectional view of a microphone package of the presentinvention;

FIG. 24 is a cross-sectional view of a microphone package of the presentinvention;

FIG. 25 is a cross-sectional view of a microphone package of the presentinvention;

FIG. 26 is a cross-sectional view of a microphone package of the presentinvention;

FIG. 27 is a cross-sectional view of a microphone package of the presentinvention with a retaining ring;

FIG. 28 is a cross-sectional view of a microphone package of the presentinvention with a retaining wing;

FIG. 29 is a cross-sectional view of a microphone package of the presentinvention with a retaining ring;

FIG. 30 is a plan view of a panel of a plurality of microphone packages;and

FIG. 31 is a plan view of a microphone pair.

DETAILED DESCRIPTION

While the invention is susceptible of embodiments in many differentforms, there is shown in the drawings and will herein be described indetail several possible embodiments of the invention with theunderstanding that the present disclosure is to be considered as anexemplification of the principles of the invention and is not intendedto limit the broad aspect of the invention to the embodimentsillustrated.

The present invention is directed to microphone packages. The benefitsof the microphone packages disclosed herein over microphone packagingutilizing plastic body/lead frames include the ability to processpackages in panel form allowing more units to be formed per operationand at much lower cost. The typical lead frame for a similarlyfunctioning package would contain between 40 and 100 devices connectedtogether. The present disclosure would have approximately 14,000 devicesconnected together (as a panel). Also, the embodiments disclosed hereinrequire minimal “hard-tooling” This allows the process to adjust tocustom layout requirements without having to redesign mold, lead frame,and trim/form tooling.

Moreover, many of the described embodiments have a better match ofthermal coefficients of expansion with the end user's PCB, typicallymade of FR-4, since the microphone package is also made primarily ofFR-4. These embodiments of the invention may also eliminate the need forwire bonding that is required in plastic body/lead frame packages. Thefootprint is typically smaller than that would be required for a plasticbody/lead frame design since the leads may be formed by plating athrough-hole in a circuit board to form the pathway to the solder pad.In a typical plastic body/lead frame design, a (gull wing configurationwould be used in which the leads widen the overall foot print.

Now, referring to FIGS. 1-3, three embodiments of a silicon condensermicrophone package 10 of the present invention are illustrated. Includedwithin silicon microphone package 10 is a transducer 12, e.g. a siliconcondenser microphone as disclosed in U.S. Pat. No. 5,870,482 which ishereby incorporated by reference and an amplifier 16. The package itselfincludes a substrate 14, a back volume or air cavity 18, which providesa pressure reference for the transducer 12, and a cover 20. Thesubstrate 14 may be formed of FR-4 material allowing processing incircuit board panel form, thus taking advantage of economies of scale inmanufacturing. FIG. 6 is a plan view of the substrate 14 showing theback volume 18 surrounded a plurality of terminal pads.

The back volume 18 may be formed by a number of methods, includingcontrolled depth drilling of an upper surface 19 of the substrate 14 toform a recess over which the transducer 12 is mounted (FIG. 1); drillingand routing of several individual sheets of FR-4 and laminating theindividual sheets to form the back volume 18, which may or may not haveinternal support posts (FIG. 2); or drilling completely through thesubstrate 14 and providing a sealing ring 22 on the bottom of the devicethat will seal the back volume 18 during surface mounting to a user's“board” 28 (FIGS. 3-5). In this example, the combination of thesubstrate and the user's board 28 creates the back volume 18. The backvolume 18 is covered by the transducer 12 (e.g., a MEMS device) whichmay be “bumpbonded” and mounted face down. The boundary is sealed suchthat the back volume 18 is operably “air-tight.”

The cover 20 is attached for protection and processability. The cover 20contains an aperture 24 which may contain a sintered metal insert 26 toprevent water, particles and/or light from entering the package anddamaging the internal components inside; i.e. semiconductor chips. Theaperture 24 is adapted for allowing sound waves to reach the transducer12. The sintered metal insert 26 will also have certain acousticproperties, e.g. acoustic damping or resistance. The sintered metalinsert 26 may therefore be selected such that its acoustic propertiesenhance the functional capability of the transducer 12 and/or theoverall performance of the silicon microphone 10.

Referring to FIGS. 4 and 5 the final form of the product is a siliconcondenser microphone package 10 which would most likely be attached toan end user's PCB 28 via a solder reflow process. FIG. 5 illustrates amethod of enlarging the back volume 18 by including a chamber 32 withinthe end user's circuit board 28.

Another embodiment of a silicon condenser microphone package 40 of thepresent invention is illustrated in FIGS. 7-10. In this embodiment, ahousing 42 is formed from layers of materials, such as those used inproviding circuit boards. Accordingly, the housing 42 generallycomprises alternating layers of conductive and non-conductive materials44, 46. The non-conductive layers 46 are typically FR-4 board. Theconductive layers 44 are typically copper. This multi-layer housingconstruction advantageously permits the inclusion of circuitry, powerand ground planes, solder pads, ground pads, capacitance layers andplated through holes pads within the structure of the housing itself.The conductive layers provide EMI shielding while also allowingconfiguration as capacitors and/or inductors to filter input/outputsignals and/or the input power supply.

In the embodiment illustrated, the housing 42 includes a top portion 48and a bottom portion 50 spaced by a side portion 52. The housing 42further includes an aperture or acoustic port 54 for receiving anacoustic signal and an inner chamber 56 which is adapted for housing atransducer unit 58, typically a silicon die microphone or a ball gridarray package (BGA). The top, bottom, and side portions 48, 50, 52 areelectrically connected, for example with a conductive adhesive 60. Theconductive adhesive may be provided conveniently in the form of suitablyconfigured sheets of dry adhesive disposed between the top, bottom andside portions 48, 50 and 52. The sheet of dry adhesive may be activatedby pressure, heat or other suitable means after the portions are broughttogether during assembly. Each portion may comprise alternatingconductive and non-conductive layers of 44, 46.

The chamber 56 may include an inner lining 61. The inner lining 61 isprimarily formed by conductive material. It should be understood thatthe inner lining may include portions of non-conductive material, as theconductive material may not fully cover the non-conductive material. Theinner lining 61 protects the transducer 58 against electromagneticinterference and the like, much like a faraday cage. The inner lining 61may also be provided by suitable electrically coupling together of thevarious conductive layers within the top, bottom and side portions 48,50 and 52 of the housing.

In the various embodiments illustrated in FIGS. 7-10 and 23-26, theportions of the housing 42 that include the aperture or acoustic port 54further include a layer of material that forms an environmental barrier62 over or within the aperture 54. This environmental barrier 62 istypically a polymeric material formed to a film, such as apolytetrafluoroethylene (PTFE) or a sintered metal. The environmentalbarrier 62 is supplied for protecting the chamber 56 of the housing 42,and, consequently, the transducer unit 58 within the housing 42, fromenvironmental elements such as sunlight, moisture, oil, dirt, and/ordust. The environmental barrier 62 will also have inherent acousticproperties, e.g. acoustic damping/resistance. Therefore theenvironmental barrier 62 is chosen such that its acoustic propertiescooperate with the transducer unit 58 to enhance the performance of themicrophone. This is particularly true in connection with the embodimentsillustrated in FIGS. 24 and 25, which may be configured to operate asdirectional microphones.

The environmental barrier layer 62 is generally sealed between layers ofthe portion, top 48 or bottom 50 in which the acoustic port 54 isformed. For example, the environmental barrier may be secured betweenlayers of conductive material 44 thereby permitting the layers ofconductive material 44 to act as a capacitor (with electrodes defined bythe metal) that can be used to filter input and output signals or theinput power. The environmental barrier layer 62 may further serve as adielectric protective layer when in contact with the conductive layers44 in the event that the conductive layers also contain thin filmpassive devices such as resistors and capacitors.

In addition to protecting the chamber 56 from environmental elements,the barrier layer 62 allows subsequent wet processing, board washing ofthe external portions of the housing 42, and electrical connection toground from the walls via thru hole plating. The environmental barrierlayer 62 also allows the order of manufacturing steps in the fabricationof the printed circuit board-based package to be modified. Thisadvantage can be used to accommodate different termination styles. Forexample, a double sided package can be fabricated having a pair ofapertures 54 (see FIG. 25), both including an environmental barrierlayer 62. The package would look and act the same whether it is mountedface up or face down, or the package could be mounted to providedirectional microphone characteristics. Moreover, the environmentalbarrier layer 62 may also be selected so that its acoustic propertiesenhance the directional performance of the microphone.

Referring to FIGS. 7, 8, and 11-13 the transducer unit 58 is generallynot mounted to the top portion 48 of the housing. This definition isindependent of the final mounting orientation to an end user's circuitboard. It is possible for the top portion 48 to be mounted face downdepending on the orientation of the transducer 58 as well as the choicefor the bottom portion 50. The conductive layers 44 of the top portion48 may be patterned to form circuitry, ground planes, solder pads,ground pads, capacitors and plated through hole pads. Referring to FIGS.1-13 there may be additional alternating conductive layers 44,non-conductive layers 46, and environmental protective membranes 62 asthe package requires. Alternatively, some layers may be deliberatelyexcluded as well. The first non-conductive layer 46 may be patterned soas to selectively expose certain features on the first conductive layer44.

FIG. 11 illustrates an alternative top portion 48 for a microphonepackage. In this embodiment, a connection between the layers can beformed to provide a conduit to ground. The top portion of FIG. 11includes ground planes and/or pattern circuitry 64 and the environmentalbarrier 62. The ground planes and or pattern circuitry 64 are connectedby pins 65.

FIG. 12 illustrates another embodiment of a top portion 48. In additionto the connection between layers, ground planes/pattern circuitry 64,and the environmental barrier 62, this embodiment includes conductivebumps 66 (e.g. Pb/Sn or Ni/Au) patterned on the bottom side to allowsecondary electrical contact to the transducer 58. Here, conductivecircuitry would be patterned such that electrical connection between thebumps 66 and a plated through hole termination is made.

FIG. 13 illustrates yet another embodiment of the top portion 48. Inthis embodiment, the top portion 48 does not include an aperture oracoustic port 54.

Referring to FIGS. 7, 8 and 14-18, the bottom portion 50 is thecomponent of the package to which the transducer 58 is primarilymounted. This definition is independent of the final mountingorientation to the end user's circuit board. It is possible for thebottom portion 50 to be mounted facing upwardly depending on themounting orientation of the transducer 58 as well as the choice for thetop portion 48 construction. Like the top portion 48, the conductivelayers 44 of the bottom portion 50 may be patterned to form circuitry,ground planes, solder pads, ground pads, capacitors and plated throughhole pads. As shown in FIGS. 14-18, there may be additional alternatingconductive layers 44, non-conductive layers 46, and environmentalprotective membranes 62 as the package requires. Alternatively, somelayers may be deliberately excluded as well. The first non-conductivelayer 46 may be patterned so as to selectively expose certain featureson the first conductive layer 44.

Referring to FIGS. 14 a through 14 d, the bottom portion 50 comprises alaminated, multi-layered board including layers of conductive material44 deposited on layers of non-conductive material 46. Referring to FIG.14 b, the first layer of conductive material is used to attach wirebonds or flip chip bonds. This layer includes etched portions to definelead pads, bond pads, and ground pads. The pads would have holes drilledthrough them to allow the formation of plated through-holes.

As shown in FIG. 14 c, a dry film 68 of non-conductive material coversthe conductive material. This illustration shows the exposed bondingpads as well as an exposed ground pad. The exposed ground pad would comein electrical contact with the conductive epoxy and form the connectionto ground of the side portion 52 and the base portion 50.

Referring to FIG. 14 d, ground layers can be embedded within the baseportion 50. The hatched area represents a typical ground plane 64. Theground planes do not overlap the power or output pads, but will overlapthe transducer 58.

Referring to FIG. 15, an embodiment of the bottom portion 50 isillustrated. The bottom portion 50 of this embodiment includes a soldermask layer 68 and alternating layers of conductive and non-conductivematerial 44, 46. The bottom portion further comprises solder pads 70 forelectrical connection to an end user's board.

FIGS. 16 and 17 illustrate embodiments of the bottom portion 50 withenlarged back volumes 18. These embodiments illustrate formation of theback volume 18 using the conductive/non-conductive layering.

FIG. 18 shows yet another embodiment of the bottom portion 50. In thisembodiment, the back portion 50 includes the acoustic port 54 and theenvironmental barrier 62.

Referring to FIGS. 7-10 and 19-22, the side portion 52 is the componentof the package that joins the bottom portion 50 and the top portion 48.The side portion 52 may include a single layer of a non-conductivematerial 46 sandwiched between two layers of conductive material 44. Theside portion 52 forms the internal height of the chamber 56 that housesthe transducer 58. The side portion 52 is generally formed by one ormore layers of circuit board material, each having a routed window 72(see FIG. 19).

Referring to FIGS. 19-22, the side portion 52 includes inner sidewalls74. The inner sidewalls 74 are generally plated with a conductivematerial, typically copper, as shown in FIGS. 20 and 21. The sidewalls74 are formed by the outer perimeter of the routed window 72 andcoated/metallized with a conductive material.

Alternatively, the sidewalls 74 may be formed by may alternating layersof non-conductive material 46 and conductive material 44, each having arouted window 72 (see FIG. 19). In this case, the outer perimeter of thewindow 72 may not require coverage with a conductive material becausethe layers of conductive material 44 would provide effective shielding.

FIGS. 23-26 illustrate various embodiments of the microphone package 40.These embodiments utilize top, bottom, and side portions 48, 50, and 52which are described above. It is contemplated that each of the top,bottom, and side portion 48, 50, 52 embodiments described above can beutilized in any combination without departing from the inventiondisclosed and described herein.

In FIG. 23, connection to an end user's board is made through the bottomportion 50. The package mounting orientation is bottom portion 50 down.Connection from the transducer 58 to the plated through holes is be madeby wire bonding. The transducer back volume 18 is formed by the backhole (mounted down) of the silicon microphone only. Bond pads, wirebonds and traces to the terminals are not shown. A person of ordinaryskilled in the art of PCB design will understand that the traces resideon the first conductor layer 44. The wire bonds from the transducer 58are be connected to exposed pads. The pads are connected to the solderpads via plated through holes and traces on the surface.

In FIG. 24, connection to the end user's board is also made through thebottom portion 50. Again, the package mounting orientation is bottomportion 50. Connection from the transducer 58 to the plated throughholes are made by wire bonding. The back volume is formed by acombination of the back hole of the transducer 58 (mounted down) and thebottom portion 50.

In FIG. 25, connection to the end user's board is also made through thebottom portion 50. Again, the package mounting orientation is bottomportion 50. Connection from the transducer 58 to the plated throughholes are made by wire bonding. With acoustic ports 54 on both sides ofthe package, there is no back volume. This method is suitable to adirectional microphone.

In FIG. 26, connection to the end user's board is made through the topportion 48 or the bottom portion 53. The package mounting orientation iseither top portion 48 down or bottom portion 50 down. Connection fromthe transducer 58 to the plated through holes is made by flip chippingor wire bonding and trace routing. The back volume 18 is formed by usingthe air cavity created by laminating the bottom portion 50 and the topportion 48 together. Some portion of the package fabrication isperformed after the transducer 58 has been attached. In particular, thethrough hole formation, plating, and solder pad definition would be doneafter the transducer 58 is attached. The protective membrane 62 ishydrophobic and prevents corrosive plating chemistry from entering thechamber 56.

Referring to FIGS. 27-29, the portion to which the transducer unit 58 ismounted may include a retaining ring 84. The retaining ring 84 preventswicking of an epoxy 86 into the transducer 58 and from flowing into theacoustic port or aperture 54. Accordingly, the shape of the retainingring 84 will typically match the shape of the transducer 58 foot print.The retaining ring 84 comprises a conductive material (e.g., 3 mil.thick copper) imaged on a non-conductive layer material.

Referring to FIG. 27, the retaining ring 84 is imaged onto anonconductive layer. An epoxy is applied outside the perimeter of theretaining ring 84, and the transducer 58 is added so that it overlapsthe epoxy 86 and the retaining ring 84. This reduces epoxy 86 wicking upthe sides of the transducer's 58 etched port (in the case of a silicondie microphone).

Alternatively, referring to FIG. 28, the retaining ring 84 can belocated so that the transducer 58 does not contact the retaining ring84. In this embodiment, the retaining ring 84 is slightly smaller thanthe foot print of the transducer 58 so that the epoxy 86 has arestricted path and is, thus, less likely to wick. In FIG. 29, theretaining ring 84 is fabricated so that it contacts the etched port ofthe transducer 58. The following tables provide an illustrative exampleof a typical circuit board processing technique for fabrication of thehousing of this embodiment.

TABLE 1 Materials Material Type Component Note 1 0.5/0.5 oz. DST BottomPortion (Conductive Cu 5 core FR-4 Layers Non-Conductive Layer 1) 20.5/0.5 oz. DST Bottom Portion (Conductive Cu 5 core FR-4 Layers 3 and4; Non- Conductive Layer 2) 3 106 pre-preg For Laminating Material 1 andMaterial 2 4 0.5/0.5 oz. DST Side Portion Metallized Cu 40 Core FR-4Afterward 5 Bare/0.5 oz. Cu 2 Top Portion (Each Piece core FR-4 (2Includes 1 Conductive and 1 pieces) Non-Conductive Layer) 6 ExpandedPTFE Environmental Barrier

TABLE 2 Processing of Materials (Base Portion Material 1) Step TypeDescription Note 1 Dry Film Conductive Layers 2 Expose Mask Material 1(Upper Forms Ground Conductive Layer) Plane on Lower Conductive Layer 3Develop 4 Etch Cu No Etching on Upper Conductive Layer 5 Strip Dry Film

TABLE 3 Processing of Materials (Bottom Portion Material 2) Step TypeDescription Note 1 Dry Film Conductive Layers 2 Expose Mask Material 2(Upper Forms Ground Conductive Layer) Plane on Upper Conductive Layer 3Develop 4 Etch Cu No Etching on Upper Conductive Layer 5 Strip Dry Film

TABLE 4 Processing of Materials 1, 2, and 3 (Form Bottom Portion) StepType Description Note 1 Laminate Materials 1 and 2 Laminated UsingMaterial 3 2 Drill Thru Holes Drill Bit = 0.025 in. 3 Direct Plates ThruHoles Metallization/Flash Copper 4 Dry Film (L1 and L4) 5 Expose MaskLaminated Forms Traces and Solder Materials 1 and 2 Pads (Upper andLower Conductive Layers) 6 Develop 7 Electrolytic Cu 1.0 mil 8Electrolytic Sn As Required 9 Strip Dry Film 10 Etch Cu 11 Etch Cu 12Insert Finishing NG Option (See NG Option for Proof Option Here TableBelow) of Principle 13 Dry Film (cover 2.5 mil Minimum Thickness lay) onUpper on Upper Conductive Conductive Layer Layer Only 14 Expose MaskLaminated This mask defines an Materials 1 and 2 area on the upper(upper and lower) conductive layer that will receive a dry film soldermask (cover lay). The bottom layer will not have dry film applied to it.The plated through holes will be bridged over by the coating on the top.15 Develop 16 Cure Full Cure 17 Route Panels Route Bit = As Forms 4″ ×4″ pieces. Required Conforms to finished dims

Table 5 describes the formation of the side portion 52. This processinvolves routing a matrix of openings in FR-4 board. However, punchingis thought to be the cost effective method for manufacturing. Thepunching may done by punching through the entire core, or,alternatively, punching several layers of no-flow pre-preg and thin corec-stage which are then laminated to form the wall of proper thickness.

After routing the matrix, the board will have to be electroless or DMplated. Finally, the boards will have to be routed to match the bottomportion. This step can be done first or last. It may make the piece moreworkable to perform the final routing as a first step.

TABLE 5 Processing of Material 4 (Side Portion) Step Type DescriptionNote 1 Route/Punch Route Bit = 0.031 in. Forms Side Portion Matrix ofOpenings 2 Direct 0.25 mil minimum Forms Sidewalls Metallization/ onSide Portion Flash Cu 3 Route Panels

Table 6 describes the processing of the top portion. The formation ofthe top portion 48 involves imaging a dry film cover lay or liquidsolder mask on the bottom (i.e. conductive layer forming the innerlayer. The exposed layer of the top portion 48 will not have a coppercoating. It can be processed this way through etching or purchased thisway as a one sided laminate.

A matrix of holes is drilled into the lid board. Drilling may occurafter the imaging step. If so, then a suitable solder mask must bechosen that can survive the drilling process.

TABLE 6 Processing of Top Portion Step Type Description Note 1 Dry FilmConductive Layer 2 Expose Mask Bare Layer Form Conduction Ring 3 Develop4 Cure 5 Drill Matrix Drill Bit 0.025 in. Acoustic Ports of Holes 6Laminate PTFE (Environmental Forms Top Portion Barrier) Between 2 Piecesof Material 5

TABLE 7 Processing of Laminated Materials 1 and 2 with Material 4 StepType Description Note 1 Screen Conductive Adhesive on Material 4 2Laminate Bottom Portion with Forms Bottom Side Portion Portion with SidePortion (spacer) 3 Add Transducer Silicon Die Microphone Assembly andIntegrated Circuit

TABLE 8 Processing of Laminated Materials 1, 2, and 4 with Material 5Step Type Description Note 1 Screen Conductive Adhesive on Top Portion 2Laminate Bottom Portion and Side Forms Housing Portion with Top Portion3 Dice

TABLE 9 Finishing Option NG (Nickel/Gold) Step Type Description Note 1Immersion Ni (40-50 μ-in) 2 Immersion Au (25-30 μ-in)

TABLE 10 Finishing Option NGT (Nickel/Gold/Tin) Step Type 1 Mask L2(using thick dry film or high tack dicing tape) 2 Immersion Ni (40-50μ-in) 3 Immersion Au (25-30 μ-in) 4 Remove Mask on L2 5 Mask L1 (usingthick dry film or high tack dicing tape) bridge over cavity created bywall 6 Immersion Sn (100-250 μ-in) 7 Remove Mask on L1

TABLE 11 Finishing Option ST (Silver/Tin) Step Type 1 Mask L2 (usingthick dry film or high tack dicing tape) 2 Immersion Ag (40-50 μ-in) 3Remove Mask on L2 4 Mask L1 (using thick dry film or high tack dicingtape) bridge over cavity created by wall 5 Immersion Sn (100-250 μ-in) 6Remove Mask on L1

FIG. 30 is a plan view illustrating a panel 90 for forming a pluralityof microphone packages 92. The microphone packages 92 are distributed onthe panel 90 in a 14×24 array, or 336 microphone packages total. Feweror more microphone packages may be disposed on the panel 90, or onsmaller or larger panels. As described herein in connection with thevarious embodiments of the invention, the microphone packages include anumber of layers, such as top, bottom and side portions of the housing,environmental barriers, adhesive layers for joining the portions, andthe like. To assure alignment of the portions as they are broughttogether, each portion may be formed to include a plurality of alignmentapertures 94. To simultaneously manufacture several hundred or evenseveral thousand microphones, a bottom layer, such as described herein,is provided. A transducer, amplifier and components are secured atappropriate locations on the bottom layer corresponding to each of themicrophones to be manufactured. An adhesive layer, such as a sheet ofdry adhesive is positioned over the bottom layer, and a sidewall portionlayer is positioned over the adhesive layer. An additional dry adhesivelayer is positioned, followed by an environmental barrier layer, anotherdry adhesive layer and the top layer. The dry adhesive layers areactivated, such as by the application of heat and/or pressure. The panelis then separated into individual microphone assemblies using knownpanel cutting and separating techniques.

The microphone, microphone package and method of assembly hereindescribed further allow the manufacture of multiple microphone assembly,such as microphone pairs. In the simplest form, during separation twomicrophones may be left joined together, such as the microphone pair 96shown in FIG. 31. Each microphone 98 and 100 of the microphone pair 96is thus a separate, individually operable microphone in a single packagesharing a common sidewall 102. Alternatively, as described herein,conductive traces may be formed in the various layers of either the topor bottom portion thus allowing multiple microphones to be electricallycoupled.

While specific embodiments have been illustrated and described, numerousmodifications come to mind without significantly departing from thespirit of the invention, and the scope of protection is only limited bythe scope of the accompanying Claims.

What is claimed is:
 1. A method for manufacturing a plurality of solderreflow surface mount microelectromechanical system (MEMS) microphones,the method comprising: providing an unsingulated panel comprised of aplurality of individual lids, wherein each lid has top and bottomsurfaces and comprises at least one conductive layer, at least onenon-conductive layer, and an acoustic port, wherein the conductive layercomprises the bottom surface of the lid, and wherein the bottom surfacehas an attachment region and an interior region, the attachment regionpositioned between the interior region and the edges of the lid, andcompletely bounding the interior region; providing an unsingulated panelcomprised of a plurality of individual sidewall spacers, wherein eachsidewall spacer has top and bottom surfaces and comprises at least twoconductive layers with a center layer of predefined thickness disposedbetween the two conductive layers, wherein one conductive layercomprises the top surface of the sidewall spacer and the otherconductive layer comprises the bottom surface of the sidewall spacer,and wherein the sidewall spacer further comprises an opening havingwalls covered with conductive material, and the opening walls extendthrough the center layer to the top surface and the bottom surface;providing an unsingulated panel comprised of a plurality of individualsubstrates, wherein each substrate comprises: a base layer comprising atleast one layer of non-conductive material, wherein the base layer has aplanar top surface and a planar bottom surface, the top surface havingan interior region and an attachment region, the attachment regiondisposed between the interior region and the edges of the base layer,and completely bounding the interior region; a first plurality of metalpads disposed on the top surface of the base layer, wherein at least onepad of the first plurality of metal pads is located in the attachmentregion of the top surface of the base layer; a second plurality of metalpads disposed on the bottom surface of the base layer, the secondplurality of metal pads arranged to be within the edges of the baselayer; and one or more electrical pathways disposed completely withinthe base layer, wherein the pathways electrically couple one or more ofthe first plurality of metal pads on the top surface of the base layerto one or more of the second plurality of metal pads on the bottomsurface of the base layer, and wherein the at least one metal padlocated in the attachment region of the top surface of the base layer iselectrically coupled to one or more of the second plurality of metalpads; mounting a MEMS microphone die on the bottom surface of eachindividual lid in the unsingulated panel of individual lids; attachingthe unsingulated panel of substrates, the unsingulated panel of sidewallspacers and the unsingulated panel of lids to each other in apredetermined order; wherein the bottom surface of each sidewall spaceris coupled to the attachment region of the top surface of its respectivesubstrate such that the opening of each sidewall spacer and the interiorregion of the top surface of each substrate are respectively aligned,and the conductive material on the opening walls of each sidewall spaceris electrically coupled to its respective at least one metal pad locatedin the attachment region of each substrate; wherein the top surface ofeach sidewall spacer is coupled to the attachment region of the bottomsurface of its respective lid such that the opening of each sidewallspacer and the interior region of the bottom surface of each lid arerespectively aligned, and the conductive layer of each lid iselectrically coupled to the conductive material on the opening walls ofits respective sidewall spacer; and wherein the interior region of thetop surface of each substrate, the opening walls of its respectivesidewall spacer, and the interior region of the bottom surface of itsrespective lid, when the panels are attached, define the internalacoustic chamber for each of their respective MEMS microphone die; andsingulating the attached panels into a plurality of individual MEMSmicrophones, wherein each substrate, and its respective sidewall spacerand lid cooperatively form a housing that has surfaces substantiallyperpendicular to the bottom surface of the substrate.
 2. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 1, wherein the method further comprises electrically coupling atleast one passive electrical element between one of the first pluralityof metal pads and one of the second plurality of metal pads.
 3. A methodfor manufacturing a plurality of surface mount MEMS microphonesaccording to claim 2, wherein the method further comprises forming theat least one passive electrical element within the base layer of thesubstrate.
 4. A method for manufacturing a plurality of surface mountMEMS microphones according to claim 2, wherein the method furthercomprises providing the at least one passive electrical element withinthe base layer of each substrate in the unsingulated panel ofsubstrates, and the at least one passive electrical element comprises adielectric or resistive material that is different from thenon-conductive material used in the base layer of each respectivesubstrate.
 5. A method for manufacturing a plurality of surface mountMEMS microphones according to claim 2, wherein the at least one passiveelectrical element is configured to filter one or more of an inputsignal, an output signal, or input power.
 6. A method for manufacturinga plurality of surface mount MEMS microphones according to claim 1,wherein the method further comprises attaching the unsingulated panel oflids to the unsingulated panel of sidewall spacers with a firstconductive material, and attaching the unsingulated panel of substratesto the unsingulated panel of sidewall spacers with a second conductivematerial.
 7. A method for manufacturing a plurality of surface mountMEMS microphones according to claim 1, wherein the housing protects theMEMS microphone die from at least one of light, electromagneticinterference, and physical damage.
 8. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 1,wherein the method further comprises providing each lid in theunsingulated panel of lids a material layer that that substantiallyblocks environmental contaminants from entering the acoustic chamberthrough the acoustic port.
 9. A method for manufacturing a plurality ofsurface mount MEMS microphones according to claim 1, wherein theacoustic port in each lid in the unsingulated panel of lids is disposedin a position offset from the centerpoint of its respective lid.
 10. Amethod for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 1, wherein the center layer of the each sidewallspacer in the unsingulated panel of sidewall spacers comprises multiplelayers of conductive and non-conductive material, and the conductivematerial on the opening walls of each sidewall spacer electricallycouples the conductive layers to each other.
 11. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 1, wherein the method further comprises plating the first andsecond pluralities of metal pads on the base layer of each substratewith a metal that is different from the metal used for the first andsecond pluralities of metal pads of each substrate in the panel ofunsingulated substrates.
 12. A method for manufacturing a plurality ofsurface mount MEMS microphones according to claim 1, wherein the baselayer of each substrate in the panel of unsingulated substrates furthercomprises at least one additional non-conductive layer and at least oneadditional conductive layer.
 13. A method for manufacturing a pluralityof surface mount MEMS microphones according to claim 1, wherein the baselayer of each substrate in the panel of unsingulated substrates furthercomprises a recess disposed therein, and its respective MEMS microphonedie is positioned over the recess.
 14. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 1,wherein the acoustic port in each lid of the panel of unsingulated lidsis a first acoustic port, and the base layer of each substrate in thepanel of unsingulated substrates further comprises a second acousticport.
 15. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 14, wherein the base layer of eachsubstrate in the unsingulated panel of substrates further comprises amaterial layer that that substantially blocks environmental contaminantsfrom entering the acoustic chamber through the second acoustic port inthe base layer.
 16. A method for manufacturing a plurality of surfacemount MEMS microphones according to claim 15, wherein, for each MEMSmicrophone, the at least one electrical element is disposed within thebase layer of the bottom portion and comprises a dielectric or resistivematerial that is different from the printed circuit board material ofthe base layer.
 17. A method for manufacturing a plurality of surfacemount MEMS microphones according to claim 16, wherein, for each MEMSmicrophone, the at least one passive electrical element is configured tofilter one or more of an input signal, an output signal, or input power.18. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 15, wherein, for each MEMS microphone,the printed circuit board layer of the spacer portion further comprisesadditional layers of printed circuit board material alternating withadditional metal layers, and the conductive material on the window wallselectrically couples the additional metal layers to each other.
 19. Amethod for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 15, wherein, for each MEMS microphone, the base layerof the bottom portion further comprises at least one additionalnon-conductive layer and at least one additional conductive layer.
 20. Amethod for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 1, wherein, for each MEMS microphone, electricalcontinuity is present between the conductive layer in its lid, theconductive material on the opening walls of its sidewall spacer, and atleast one of its second plurality of metal pads.
 21. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 1, wherein the at least one non-conductive layer of the lid, thecenter layer of non-conductive material of the sidewall spacer, and theat least one layer of non-conductive material of the base layer eachhave a substantially similar predetermined coefficient of thermalexpansion.
 22. A method for manufacturing a plurality of solder reflowsurface mount microelectromechanical system (MEMS) microphones, themethod comprising: providing an unsingulated panel comprised of aplurality of individual top portions, wherein each top portion has upperand lower surfaces and comprises at least one metal layer, at least oneprinted circuit board material layer, and an acoustic port, wherein themetal layer comprises the lower surface of the top portion, and whereinthe lower surface has a coupling area and an inner area, the couplingarea being arranged between the inner area and the edges of the topportion, and completely surrounding the inner area; providing anunsingulated panel comprised of a plurality of individual spacerportions, wherein each sidewall portion has upper and lower surfaces andcomprises at least two metal layers with a printed circuit boardmaterial layer of predefined thickness disposed between the two metallayers, wherein one metal layer comprises the upper surface of thespacer portion and the other metal layer comprises the lower surface ofthe spacer portion, and wherein the spacer portion further comprises awindow having walls covered with a metal layer, and the window wallsextend through the printed circuit board material layer to the uppersurface and the lower surface; providing an unsingulated panel comprisedof a plurality of individual bottom portions, wherein each bottomportion comprises: a base layer that comprises at least one layer ofprinted circuit board material, wherein the base layer has asubstantially flat upper surface and a substantially flat lower surface,the upper surface having an inner area and a coupling area, the couplingarea located between the inner area and the edges of the base layer, andcompletely surrounding the inner area; a plurality of metal pads locatedon the upper surface of the base layer, wherein at least one pad of theplurality of metal pads is positioned in the coupling area of the uppersurface of the base layer; a plurality of solder pads located on thelower surface of the base layer, the plurality of solder pads arrangedto be within the edges of the base layer; one or more electricalconnections passing through the base layer, wherein the connectionselectrically couple one or more of the plurality of metal pads on theupper surface of the base layer to one or more of the plurality ofsolder pads on the lower surface of the base layer, and wherein the atleast one metal pad positioned in the coupling area of the upper surfaceof the base layer is electrically coupled to one or more of theplurality of solder pads; and at least one passive electrical elementelectrically coupled between one of the plurality of metal pads and oneof the plurality of solder pads; physically coupling a MEMS microphonedie on the lower surface of each individual top portion in theunsingulated panel of individual top portions; physically coupling theunsingulated panel of top portions, the unsingulated panel of spacerportions, and the unsingulated panel of bottom portions to each other ina predetermined order; wherein a conductive material physically couplesthe lower surface of each spacer portion to the coupling area of theupper surface of its respective bottom portion such that the window ofeach spacer portion and the inner area of the upper surface of eachbottom portion are respectively aligned, and the metal layer on thewindow walls of each spacer portion is electrically coupled to the atleast one metal pad positioned in the coupling area of its respectivebottom portion; wherein a conductive material physically couples theupper surface of the spacer portion to the coupling area of the lowersurface of its respective top portion such that the window of the spacerportion and the inner area of the lower surface of its respective topportion are aligned, and the metal layer of the top portion iselectrically coupled to the metal layer on the window walls of itsrespective spacer portion; wherein electrical continuity is presentbetween the metal layer in each top portion, its respective metal layeron the window walls of its respective spacer portion, and its respectiveat least one of the plurality of solder pads; and wherein the inner areaof the upper surface of each bottom portion, the window walls of itsrespective spacer portion, and the inner area of the lower surface ofits respective top portion, when the panels are coupled, define theinternal acoustic chamber for each of their respective MEMS microphonedie; singulating the coupled panels into a plurality of individual MEMSmicrophones, wherein each bottom portion, and its respective spacerportion and top portion cooperatively form a housing that has surfacessubstantially perpendicular to the lower surface of the bottom portionand that protects the MEMS microphone die from at least one of light,electromagnetic interference, and physical damage.
 23. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 22, wherein, for each MEMS microphone, the housing furthercomprises a material that substantially blocks environmentalcontaminants from entering the acoustic chamber through the acousticport.
 24. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 22, wherein the acoustic port in each topportion in the unsingulated panel of top portions is disposed in aposition offset from the centerpoint of its respective top portion. 25.A method for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 22, wherein the acoustic port in each top portion inthe panel of unsingulated top portions is a first acoustic port, and thebase layer of each bottom portion in the panel of unsingulated bottomportions further comprises a second acoustic port.
 26. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 22, wherein, for each MEMS microphone, the housing furthercomprises a material that substantially blocks environmentalcontaminants from entering the acoustic chamber through the secondacoustic port.
 27. A method for manufacturing a plurality of surfacemount MEMS microphones according to claim 26, wherein, for each MEMSmicrophone, the first enclosure element further comprises additionalmetal layers alternating with the FR-4 printed circuit board materiallayers, and the metal layer of the interior open volume wallselectrically couples the additional metal layers to each other.
 28. Amethod for manufacturing a plurality of solder reflow surface mountmicroelectromechanical system (MEMS) microphones, the method comprising:providing an unsingulated panel comprised of a plurality of individualbase substrates, wherein each base substrate comprises: a core layercomprised of at least one layer FR-4 printed circuit board material,wherein the core layer has a substantially flat top surface and asubstantially flat bottom surface, the top surface having a die mountregion and an attachment region, the attachment region positionedbetween the die mount region and the edges of the core layer, andcompletely surrounding the die mount region; a plurality of metal padslocated on the top surface of the core layer, wherein at least one padof the plurality of metal pads is located in the attachment region ofthe top surface of the core layer; a plurality of solder pads located onthe bottom surface of the core layer, the plurality of solder padsarranged to be within the edges of the core layer; and a plurality ofelectrical connections passing through the core layer that electricallycouple one or more of the plurality of metal pads on the top surface ofthe core layer to one or more of the plurality of solder pads on thebottom surface of the core layer, and wherein the at least one metal padlocated in the attachment region of the top surface of the core layer iselectrically coupled to one or more of the plurality of solder pads;providing a plurality of enclosure elements, the plurality comprising:an unsingulated panel comprised of a plurality of individual firstenclosure elements, wherein each first enclosure element havingsubstantially flat top and bottom surfaces and comprises at least twometal layers with multiple FR-4 printed circuit board material layers ofpredefined thickness disposed between the two metal layers, wherein onemetal layer comprises the top surface of the first enclosure element andthe other metal layer comprises the bottom surface of the firstenclosure element; an unsingulated panel comprised of a plurality ofindividual second enclosure elements, wherein each second enclosureelement has top and bottom surfaces and comprises at least one metallayer, at least one FR-4 printed circuit board material layer, and anacoustic port that is disposed in an offset position from thecenterpoint of the second enclosure element, wherein the metal layercomprises the bottom surface of the second enclosure element, andwherein the bottom surface has an attachment region and an inner region,the attachment region being arranged between the attachment region andthe edges of the second enclosure element, and completely surroundingthe attachment region; mounting a pressure-equalizing MEMS microphonedie having an internal acoustic channel in the inner region of eachindividual second enclosure element in the panel of unsingulated panelof second enclosure elements; physically coupling the unsingulated panelof first enclosure elements and the unsingulated panel of secondenclosure elements to each other to form an unsingulated panel ofenclosures, wherein the top surface of each first enclosure element isphysically coupled to the attachment region of the bottom surface of itsrespective second enclosure element with a conductive material; whereineach first enclosure element further comprises an interior open volumewith walls, thereby exposing the inner region of the bottom surface ofits respective second enclosure element; and wherein the interior openvolume walls of each first enclosure element have a metal layer that iselectrically connected to the bottom surface metal layer of itsrespective second enclosure element; joining the unsingulated panel ofbase substrates and the unsingulated panel of enclosures to form ahousing that has an internal acoustic chamber for the MEMS microphonedie, and that protects the MEMS microphone die from at least one oflight, electromagnetic interference, and physical damage, wherein thebottom surface metal layer of each first enclosure element is physicallyjoined to the attachment region of its respective base substrate with aconductive material, and wherein the interior open volume of each firstenclosure element is aligned with the die mount region of its respectivebase substrate, and the metal pad positioned in each attachment regionis electrically coupled to the metal layer of the interior open volumewalls in its respective first enclosure element; wherein the interiorregion of the bottom surface of each second enclosure element, theinterior open volume walls of its respective first enclosure element,and the die mount region of its respective base substrate define theacoustic chamber for its respective MEMS microphone die; whereinelectrical continuity exists between the metal layer of each secondenclosure element, the metal-covered interior open volume walls of itsrespective enclosure element, and one or more of the plurality of solderpads on its respective base substrate; and singulating the coupledpanels into a plurality of individual MEMS microphones, wherein, foreach MEMS microphone, the length of the base substrate and the length ofthe enclosure are substantially equal, and the width of the basesubstrate and the width of the enclosure are substantially equal.
 29. Amethod for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 28, the method further comprising providing at leastone passive electrical element within the core layer of each basesubstrate in the unsingulated panel of base substrates, and electricallycoupling the at least one passive electrical element between one of theplurality of metal pads and one of the plurality of solder pads.
 30. Amethod for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 28, wherein, for each MEMS microphone, the housingfurther comprises a material that substantially blocks environmentalcontaminants from entering the acoustic chamber through the acousticport of the MEMS microphone.
 31. A method for manufacturing a pluralityof surface mount MEMS microphones according to claim 28, wherein theacoustic port in each secon denclosure element of the unsingulated panelof second enclosure elements is a first acoustic port, and the corelayer of each base substrate in the unsingulated panel of basesubstrates further comprises a second acoustic port.
 32. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 31, wherein, for each MEMS microphone, the housing furthercomprises a material that substantially blocks environmentalcontaminants from entering the acoustic chamber through the secondacoustic port of the MEMS microphone.
 33. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 32,wherein the core layer of each third housing element in the panel ofunsingulated third housing elements comprises at least one passiveelectrical element disposed within the core layer of the third housingelement and comprises a dielectric or resistive material that isdifferent from the printed circuit board material of the core layer. 34.A method for manufacturing a plurality of surface mount MEMS microphonesaccording to claim 27, wherein the at least one passive electricalelement is configured to filter one or more of an input signal, anoutput signal, or input power.
 35. A method for manufacturing aplurality of surface mount MEMS microphones according to claim 31,wherein, for each MEMS microphone, the second housing element furthercomprises additional metal layers interposed between the multiple layersof printed circuit board material, and the metal-covered walls of theaperture electrically couples the additional metal layers to each other.36. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 28, wherein the core layer of the eachbase substrate in the unsingulated panel of base substrates comprises atleast one passive electrical element is disposed within the core layerof the base substrate and comprises a dielectric or resistive materialthat is different from the FR-4 printed circuit board material of thecore layer.
 37. A method for manufacturing a plurality of surface mountMEMS microphones according to claim 19, wherein, for each MEMSmicrophone, the at least one passive electrical element is configured tofilter one or more of an input signal, an output signal, or input power.38. A method for manufacturing a plurality of solder reflow surfacemount microelectromechanical system (MEMS) microphones, the methodcomprising: providing a plurality of pressure-equalizing MEMS microphonedie, each MEMS microphone die having an internal acoustic channel;providing an unsingulated panel comprised of a plurality of individualfirst housing elements, wherein each first housing element hassubstantially flat top and bottom surfaces and comprises at least onemetal layer, at least one printed circuit board material layer, and anacoustic port, wherein the metal layer comprises the bottom surface ofthe first housing element, wherein the bottom surface has an attachmentregion and an interior region, the attachment region located between theinterior region and the edges of the first housing element andcompletely surrounding the interior region, and wherein the acousticport is disposed in a position offset from the centerpoint of the firsthousing element; providing an unsingulated panel comprised of aplurality of individual second housing elements, wherein each secondhousing element has substantially flat top and bottom surfaces andcomprises at least first and second metal layers with multiple printedcircuit board material layers of predefined thickness disposed betweenthe first and second metal layers, wherein the first metal layercomprises the top surface of the second housing element and the secondmetal layer comprises the bottom surface of the second housing element,wherein the second housing element further comprises an aperture havingmetal-covered walls, and the aperture walls extend through the printedcircuit board material layer to the top and bottom surfaces of thesecond housing element; providing an unsingulated panel comprised of aplurality of individual third housing elements, wherein each thirdhousing element comprises: a core layer comprised of at least one layerof printed circuit board material, wherein the core layer has asubstantially flat top surface and a substantially flat bottom surface,wherein the top surface has an interior region and an attachment region,the attachment region being arranged between the interior region and theedges of the core layer, and the attachment region completely surroundsthe interior region; a plurality of metal pads disposed on the topsurface of the core layer, wherein at least one pad of the plurality ofmetal pads is positioned in the attachment region of the top surface ofthe core layer; a plurality of solder pads disposed on the bottomsurface of the core layer, the plurality of solder pads arranged to bewithin the edges of the core layer; and one or more electrical viaslocated inside the core layer, wherein the vias electrically couple oneor more of the plurality of metal pads on the top surface of the corelayer to one or more of the plurality of solder pads on the bottomsurface of the core layer, and wherein a via electrically couples the atleast one metal pad positioned in the attachment region of the topsurface of the core layer to one or more of the plurality of solderpads; mounting one of the plurality of MEMS microphone die to the bottomsurface of each first housing element in the panel of unsingulated firsthousing elements; attaching the unsingulated panel of first housingelements, the unsingulated panel of second housing elements, and theunsingulated panel of third housing elements to each other in apredetermined order; wherein a conductive material physically couplesthe attachment region of the bottom surface of each first housingelement to the top surface of its respective second housing element tosuch that the interior region of the bottom surface of each firsthousing element and the aperture of its respective second housingelement are aligned, and the metal layer of each first housing elementis electrically coupled to the metal-covered aperture walls of itsrespective second housing element; wherein a conductive materialphysically couples the bottom surface of each second housing element tothe attachment region of the top surface of its respective third housingelement such that the aperture of each second housing element and theinterior region of the top surface of its respective third housingelement are aligned, and the metal-covered aperture walls of each secondhousing element are electrically coupled to the at least one metal padpositioned in the attachment region of the its respective housingelement; wherein the interior region of the bottom surface of each firsthousing element, the aperture walls of its respective second housingelement, and the interior region of the top surface of its respectivethird housing element, when the panels are attached, define an internalacoustic chamber for its respective MEMS microphone die; and whereinelectrical continuity exists between the metal layer of each firsthousing element, the metal-covered aperture walls of its respectivesecond housing element, and one or more of the plurality of solder padson its respective third housing element; and singulating the coupledpanels into a plurality of individual MEMS microphones, wherein thefirst housing element, and its respective second, and third housingelements cooperatively form a housing that has surfaces substantiallyperpendicular to the bottom surface of the third housing element, thathas the internal acoustic chamber for the MEMS microphone die, and thatprotects the MEMS microphone die from at least one of light,electromagnetic interference, and physical damage.
 39. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 38, wherein the method further comprises electrically coupling atleast one passive electrical element between one of the plurality ofmetal pads and one of the plurality of solder pads.
 40. A method formanufacturing a plurality of surface mount MEMS microphones according toclaim 32, wherein, for each MEMS microphone, the housing furthercomprises a material that substantially blocks environmentalcontaminants from entering the acoustic chamber through the acousticport.
 41. A method for manufacturing a plurality of surface mount MEMSmicrophones according to claim 38, wherein the acoustic port of eachfirst housing element in the unsingulated panel of first housingelements is a first acoustic port, and each third housing element in theunsingulated panel of third housing elements further comprises a secondacoustic port.
 42. A method for manufacturing a plurality of surfacemount MEMS microphones according to claim 41, wherein, for each MEMSmicrophone, the housing further comprises a material that substantiallyblocks environmental contaminants from entering the acoustic chamberthrough the second acoustic port.